Don't Appal Me When I'm High
by chasingriver
Summary: "Brother-mine… don't appal me when I'm high." Sherlock twisted his arm painfully behind his back and slammed him against the wall. Mycroft blinked, open-mouthed and gasping, partially from the pain but mostly from surprise. He'd forgotten how strong Sherlock was when he was like this; how violent. He should have been terrified.


**Betas:** deklava, youcantsaymylastname  
**Warnings:**  
Sibling incest.  
Dub-con, sort of. Not really. And probably not in the way you're expecting. If in doubt, go and check the tags on the AO3 version first.

* * *

Mycroft didn't keep many secrets from Sherlock, but Magnussen was one of them.

"Brother-mine… don't appal me when I'm high."

Sherlock twisted his arm painfully behind his back and slammed him against the wall.

Mycroft blinked, open-mouthed and gasping, partially from the pain but mostly from surprise. He'd forgotten how strong Sherlock was when he was like this; how violent. He should have been terrified. His expression almost certainly read that way to John—a small blessing, really. The rush of adrenaline hit his bloodstream in the same way he imagined the cocaine hit Sherlock's.

"Get out, John," Sherlock said calmly. "I need to have a few words with Mycroft." He pushed Mycroft's arm further up his back, sending another shock of pain through him. "I'll stop by later."

"Are… are you sure? I thought you were going to—"

"_Later_, John."

"Right. I'll just go, then."

Mycroft didn't even look at John, concerned that he might betray his _mixed_ emotions about the situation. Certainly, Sherlock's involvement with Magnussen was nothing short of a disaster, and the drug use was just as problematic, but it was hard to think straight when his brother had him pinned against a wall like this. It was obscene. Well, in a certain context.

As the door shut behind John, Sherlock closed in.

"How dare you, Mycroft? You can't order me around anymore," he said, holding him there like one of his science experiments.

"Oh, I disagree," Mycroft replied, wondering how far he could push him. He sucked in another gasp of pain as Sherlock wrenched his arm again. If this had been anyone else, he would have had them on the floor by now, dead or immobilised, but this was Sherlock: he'd never hurt his little brother.

Sherlock, for all his sniping and petulance, was generally non-confrontational. His anger rarely escalated beyond a wicked sulk—unless he was high as a kite and very, very upset. When that happened, he got furious. And _malleable_. Mycroft certainly wasn't about to miss _that_ opportunity. A simple 'Unwise, brother-mine' was all it took to make Sherlock forget all about John and turn his bright focus onto him. _Easy._

"You're such a condescending bastard, always telling me what to do. I've got this completely under control."

"You're still mourning John and you wanted an excuse to get high."

Sherlock fisted his suit and pulled him back, then slammed Mycroft against the wall so hard his head ricocheted against it. His vision swam for a moment before it resolved. _There. Almost too easy, really._

Sherlock pinned him against the wall with his body, one hand gripping Mycroft's wrist entirely too hard and the other around his throat, squeezing. _Just where I want you, Sherlock._ The compression of his carotid artery added a warm buzz to the heat from his brother's torso. He could feel Sherlock, erect and hard against his back. Cocaine always made him like this—angry, and desperate, and _aroused._

He must have started to slump from the hypocapnia, because Sherlock let go of his neck and yanked his head back by his hair instead. The rush of oxygen and the sudden pain hit him like a bright light and he grunted. Sherlock seemed pleased.

"You're going to learn not to patronise me. I can take care of myself."

Mycroft gave a short laugh.

Sherlock grabbed his tie and dragged him into the middle of the kitchen. When he shoved him to the floor, Mycroft got a close-up view of the bulge in his sweatpants—right before Sherlock pushed them down and pulled out his cock. He held Mycroft's head in place as he tried to push it between his lips, but Mycroft kept his mouth closed and it slid awkwardly across his cheek. _Mustn't look too enthusiastic._

Sherlock slapped him, hard, and the pain made Mycroft gasp—and open his mouth. He shoved his cock inside, too fast and too deep. When it hit the back of his throat, he gagged, and Sherlock held him there for a few seconds as his body tried to fight it. Then he pulled out a bit, but kept his hand fisted tightly in his brother's neatly-combed hair.

"Suck," he said, his voice a mixture of brutality and arousal.

Mycroft tried to pull away, hoping for a reaction. He wanted some bruises out of this, at the very least. After Sherlock came down, they always pretended these things never happened—it was nice to enjoy the physical proof for as long as he could. Sherlock kneed him in the chest and shoved his cock deep again. _Yes… good boy. So predictable._ There was nothing tentative about his brother's movements now—he fucked Mycroft's face hard and fast, every now and again choking him until he gagged. His eyes watered, and he struggled to hold it together. If he looked too pathetic, Sherlock might stop.

"I can't decide if I want to come all over your smug face or make you swallow me," he said, pulling out—presumably for Mycroft to give him an answer that he'd then ignore.

_Time to see if I can get what I really want out of this. _

"I'm sure that deluded girl in your bedroom would love the same choice."

Sherlock's eyes flashed with rage. "How did you—"

"I do my _research_, Sherlock. You should try it sometime." Smug; irritating; maximum condescension per word.

Sherlock pulled him to his feet with his tie and shoved him in the direction of the kitchen table.

_Oh, a miscalculation._ He'd expected it to be the countertop. Mycroft swept his arm forward as he fell, pushing the lab glass that covered the table out in front of him. He didn't want stitches from this little encounter. Only one piece fell off, and it hit the floor with a thud, not a crash. It wouldn't have been too damning if Janine had come running in: he was still fully dressed, and Sherlock could pull up his trousers easily enough. They could chalk the entire thing up to a shoving match, but it would have put an end to their fun.

Sherlock slammed Mycroft's chest against the table top and jabbed his elbow into one of his kidneys.

Mycroft hoped his groan of pain didn't sound too _satisfied._ He'd take any sort of contact he could get.

Sherlock undid Mycroft's trousers and tried to pull them down, but his braces prevented it. Sherlock didn't suspect a thing as he worked the zip: Mycroft had been careful not to let himself get hard. It wouldn't do to let his brother know how much he _enjoyed_ this. There'd be plenty of time to pleasure himself later—to every filthy second of it.

"Fucking Victorian suits," Sherlock muttered and pulled down harder this time. The buttons gave out before the material did, and they went skittering along the kitchen floor as Mycroft's trousers ended up around his ankles. His boxers were next, and now it really would have been incriminating, with him bent over the table half-naked like this. Not that he cared—people were easy enough to silence. He was far more concerned about the potential damage to his suit, but he'd happily leave here with it in tatters if things kept going like this.

Sherlock was rarely considerate—even less so when high. Mycroft doubted he owned lubricant, and suggesting some sort of kitchen oil seemed mildly pathetic. Sherlock had never had a cock up his arse; it was unlikely he'd investigated the logistics, let alone the sensation. One day, Mycroft would fix that. It didn't matter though; his brother wasn't huge, and a little pain was tolerable, even desirable. His saliva would be adequate to prevent injury, but it would hurt—just enough. His heart raced as he waited, bent bare-arsed over the kitchen table. There was a fine line between faking vulnerability and revealing his anticipation. Too much of either, and Sherlock would be put off. Fear. Submission. That's what his brother was looking for.

He pushed up on his elbows and turned his head slightly, the look on his face broadcasting every emotion Sherlock wanted to see. His brother was staring back at him, looking wild. Undone. Smudges of dirt—and now a sheen of sweat—covered his face, and there was an air of desperation about him.

"This is the last time you humiliate me," Sherlock said, looking down at him with a grim sort of satisfaction. He pushed him down onto the table again and wrapped a hand across his mouth. "And not a word out of you, unless you want an audience."

Mycroft nodded. When Sherlock lined up and forced himself inside with one hard shove, he was glad for the makeshift gag. One day, he'd teach him how to do this properly, but _God_, this was good in its own way. The pain made his nerves sing, and the stretch and burn of his brother inside of him, pounding him relentlessly, was like a cleansing fire.

In one last act of control _(would Sherlock ever realise he wasn't in control during these encounters?)_, he orchestrated Sherlock's orgasm. It was true, he couldn't force the build-up—a certain amount of physics was necessary after all—but once he was close, all it took was one little psychological detail to send him crashing over the edge.

He tried to get away.

Sherlock slipped his hand possessively onto Mycroft's neck and squeezed. Then, with a groan, he slammed into him one final time and emptied out deep inside of him.

Mycroft smiled. _Good boy._

Sherlock pulled out of him and cleaned himself up, all the rage apparently diffused. Without saying a word, he went over to his chair and started working on his computer.

Mycroft simply got dressed. He took perverse pleasure in the thought of his brother's release leaking out onto his silk boxers as he rode home in the limo. Better still, he might be able to retain enough to use it as a masturbatory lubricant when he got home.

He looked suitably chastened as he left the flat, and he had no doubt that Sherlock remained completely unaware that he'd been coerced into the entire thing.

Mycroft didn't keep many secrets from Sherlock, but this was one of them.


End file.
